Data distribution device and imaging apparatus

ABSTRACT

A data distribution device for stably distributing specific data such as video data is provided. Video distribution device as a data distribution device includes video distribution unit as a specific data distribution unit, video distribution determining unit as a specific data distribution determining unit, and routing setting unit. When video distribution determining unit determines that video distribution unit is distributing video data as the specific data, and when the default route information has been acquired from a second communication device connected to a second network, routing setting unit holds the default route information without changing the default route.

RELATED APPLICATIONS

This application claims the benefit of Japanese Application No.2014-057475, filed on Mar. 20, 2014 and Japanese Application No.2014-245493, filed on Dec. 4, 2014, the disclosures of whichApplications are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a data distribution device and imagingapparatus for distributing specific data such as video data via anetwork to an external device connected to the network.

2. Background Art

A communication device is known that, when it connects to a network,acquires routing information including default route information using acommunication protocol such as a DHCP (Dynamic Host ConfigurationProtocol) or PPP (Point to Point Protocol), and performs automaticsetting. This communication device does not require the network settingby a user.

The routing information means the information indicating a transferroute of an IP (Internet Protocol) packet (which means data in a formcapable of being handled on a network, and is referred to also as“packet”) on a network. The default route information means the routinginformation that indicates an IP address (serving as the transferdestination of the IP packet) used when the transmission source does notknow the transfer destination of the IP packet. For example, uponacquiring default information, a device as the transmission source ofthe IP packet sets a default route in accordance with the default routeinformation, and transfers, along the default route, the IP packet whosetransfer destination is not known.

A computer terminal (simply referred to also as “terminal”) is knownthat includes a plurality of communication devices including a firstcommunication device and a second communication device and can beconnected to a plurality of networks. This terminal can be connected toone network (e.g. first network) using the first communication device,and can be connected to another network (e.g. second network) using thesecond communication device.

However, this terminal acquires routing information from one network andperforms automatic setting, so that the communication via anothernetwork is sometimes disabled. For example, the terminal is connected tothe first network via the DHCP using the first communication device. Inthis state, the terminal can perform communication via the firstnetwork. Then, the terminal is connected to the second network via theDHCP using the second communication device. In this case, the routinginformation set when the terminal is connected to the first network isupdated to the routing information acquired via the second communicationdevice. Therefore, the terminal transmits all of subsequent data(transmission packets) via the second network.

Thus, when the routing information (default route) is automaticallyupdated, the following problems can occur, for example.

(1) Although the communication state where specific data is transmitted(for example, video distribution by streaming) via a first network (forexample, network allowing high-speed communication) is intended to bekept, the default route is changed so that the communication isperformed via a second network (for example, a network having arelatively low communication speed). Therefore, a trouble (for example,a temporary halt of streaming) occurs in transmission of the specificdata.(2) This terminal cannot communicate, via a second network, with aterminal as the communication partner with which this terminal hascommunicated via a first network. Here, the first network is a publicline network such as LTE (Long Term Evolution), and the second networkis LAN (Local Area Network) that is not connected to the Internet, forexample. Therefore, the switching of the default route from the firstnetwork to the second network disables the data transmission (e.g. videodistribution) to the terminal as the communication partner.

Unexamined Japanese Patent Publication No. 2006-067105 (PatentLiterature 1) discloses a method in which the routing informationindicating the combination of a preset specific communication partnerand a specific communication device is previously registered, and acommunication route (routing) is set in accordance with the combination.In this method, even when the routing information is updated uponconnection to each network, the communication using the specificcommunication device can be kept for the preset specific communicationpartner.

In this method, however, the routing information indicating thecombination of the specific communication partner and the specificcommunication device must be previously set in the terminal, and thesetting must be changed when the IP address of the communication partneror the IP address of the router included in the routing information ischanged.

SUMMARY OF THE INVENTION

The present disclosure provides a data distribution device capable ofbeing connected to a plurality of networks using a plurality ofcommunication devices.

The data distribution device of the present disclosure includes aspecific data distribution unit, a specific data distributiondetermining unit, and a routing setting unit. The specific datadistribution unit is configured to distribute specific data from thefirst communication device connected to the first network. The specificdata distribution determining unit is configured to determine whether ornot the specific data distribution unit is distributing the specificdata. The routing setting unit is configured to, based on thedetermination result by the specific data distribution determining unit,use the default route information acquired from the network to changethe default route. The routing setting unit is also configured to holdthe default route information without changing the default route whenthe specific data distribution determining unit determines that thespecific data distribution unit is distributing the specific data andwhen the default route information has been acquired from the secondcommunication device connected to the second network.

The imaging apparatus of the present disclosure includes theabove-mentioned data distribution device and an imaging unit capable ofperforming video shooting, and is configured to set, as the specificdata, video data output from the imaging unit.

The data distribution device and imaging apparatus of the presentdisclosure is useful for improving the stability when specific data isdistributed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram schematically showing one example of networkconnection of an imaging apparatus including a video distribution devicein accordance with a first exemplary embodiment;

FIG. 2 is a block diagram schematically showing one configurationexample of the video distribution device in accordance with the firstexemplary embodiment;

FIG. 3 is a flowchart schematically showing one example of a defaultroute setting operation when the video distribution device acquiresdefault route information in accordance with the first exemplaryembodiment;

FIG. 4 is a flowchart schematically showing one example of a defaultroute setting operation when the video distribution device stops videodistribution in accordance with the first exemplary embodiment; and

FIG. 5 is a flowchart schematically showing one example of the IP packettransmitting operation of the video distribution device in accordancewith the first exemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the exemplary embodiments will be described in detailappropriately with reference to the accompanying drawings. Descriptionmore detailed than necessary is sometimes omitted. For example, adetailed description of a well-known item and a repeated description ofsubstantially the same configuration are sometimes omitted. This is forthe purpose of preventing the following descriptions from becoming moreredundant than necessary and allowing persons skilled in the art toeasily understand the exemplary embodiments.

The accompanying drawings and the following descriptions are provided toallow the persons skilled in the art to sufficiently understand thepresent disclosure. It is not intended that they restrict the mainsubject described within the scope of the claims.

First Exemplary Embodiment

The first exemplary embodiment is hereinafter described using FIG. 1 toFIG. 5.

In the present exemplary embodiment, video distribution device 100 isemployed as one example of the data distribution device, and video datais employed as one example of the specific data. Furthermore, aconfiguration example where video distribution device 100 is included inimaging apparatus 10 and distributes the video data output from imagingunit 105 is described.

In the present disclosure, however, the specific data is not limited tovideo data, and the data distribution device is not limited to videodistribution device 100. An apparatus including the data distributiondevice is not limited to imaging apparatus 10, either. For example, theconfiguration may be employed where the data distribution device isincluded in a game server and distributes game data as the specificdata. Alternatively, the configuration may be employed where the datadistribution device is included in a voice distribution device anddistributes voice data as the specific data. Alternatively, the specificdata may be billing data or the like.

In the following description, “video data” can be replaced with“specific data”, “video distribution” can be replaced with “specificdata distribution”, and “video distribution device” can be replaced with“data distribution device”

[1-1. Configuration]

[1-1-1. Network Connection Configuration]

FIG. 1 is a diagram schematically showing one example of networkconnection of imaging apparatus 10 including video distribution device100 in accordance with the first exemplary embodiment.

Imaging apparatus 10 includes imaging unit 105 capable of performingvideo shooting and video distribution device 100 as a data distributiondevice.

Imaging apparatus 10 is a professional-use digital video camera having anetwork connecting function, for example. However, imaging apparatus 10is not limited to the professional-use digital video camera. Forexample, imaging apparatus 10 may be a still image photographingapparatus that has a network connecting function and can perform videoshooting, a consumer-use digital video camera having a networkconnecting function, or a smartphone, mobile phone, tablet terminal, orpersonal computer capable of performing video shooting. Alternatively,imaging apparatus 10 may be a video signal processing apparatus ormoving-picture reproducing apparatus (e.g. video player) that has anetwork connecting function and does not include imaging unit 105.

Imaging unit 105 is configured to shoot a moving image, convert it intodigital video data, and output the video data. The function andconfiguration of imaging unit 105 are substantially the same as thefunction and configuration of a typically used digital video camera, sothat the descriptions thereof are omitted.

Video distribution device 100 is configured to be capable of beingconnected to first network 200 connected to Internet 220 and secondnetwork 210 connected to Internet 220.

Video distribution device 100 is configured so that it can distribute,via first network 200, the video data output from imaging unit 105 tovideo receiving terminal 300 connected to Internet 220. This operationis hereinafter referred to also as “video distribution”. Videodistribution device 100 is also configured so that it can performcommunication other than video distribution, such as the access to WWW(World Wide Web), file transfer to server 400, or transmission orreception of an electronic mail, and can transmit data via secondnetwork 210 in performing this communication during the videodistribution.

In the present exemplary embodiment, the data transmitted via secondnetwork 210 during the video distribution is referred to as “generaldata”, in order to distinguish from video data (specific data)distributed to video receiving terminal 300 via first network 200.

Video receiving terminal 300 is connected to Internet 220, and iscommunicably connected to video distribution device 100 via Internet 220and first network 200. Video receiving terminal 300 is configured sothat it can receive the video data distributed from video distributiondevice 100 and can reproduce or hold the video data.

The network may be configured so that video receiving terminal 300 cancommunicate with video distribution device 100 via Internet 220 andsecond network 210. In the present exemplary embodiment, however, videodistribution device 100 is configured so that the video distribution tovideo receiving terminal 300 is performed via first network 200, but isnot performed via second network 210 (described later).

Server 400 is connected to Internet 220, and is communicably connectedto video distribution device 100 via Internet 220 and second network210. Server 400 is used when video distribution device 100 performscommunication other than video distribution, such as the access to WWW,file transfer to server 400, and transmission or reception of anelectronic mail (namely, when it performs communication of generaldata). FIG. 1 shows one server 400, but the number of servers 400 may betwo or more. These servers 400 may include a typical terminal or networkdevice.

The network may be configured so that server 400 can communicate withvideo distribution device 100 via Internet 220 and first network 200.Video distribution device 100 of the present exemplary embodiment maycommunicate with server 400 via first network 200 when the videodistribution is not being performed.

First network 200 and second network 210 are communication networks(networks) such as LTE, WiFi (Wireless Fidelity), LAN, and satellitecommunication. In the present exemplary embodiment, however, firstnetwork 200 and second network 210 are not limited to these networks.Each network may be any network as long as video distribution device 100can be communicably connected to video receiving terminal 300 and server400.

The video data, transmitted from video distribution device 100 to videoreceiving terminal 300 when video distribution device 100 distributesvideo data to video receiving terminal 300, is video data that isprocessed substantially in real time for streaming-distributing themoving image shot by imaging unit 105, for example. Thus, the specificdata of the present exemplary embodiment may be stream data fordistributing, in real time, the video data output from imaging unit 105.This real time includes delay time required for each processing andtransmission.

The general data transmitted from video distribution device 100 toserver 400 may include data in the video file that is created by storingthe video data output from imaging unit 105 into a data storage unit(not shown).

Imaging apparatus 10 is configured so that it can be used as below, forexample. In order to live broadcast moving images (e.g. news video) inshooting, imaging apparatus 10 streaming-distributes, to video receivingterminal 300, data (video data) of the moving images shot by imagingunit 105. Video receiving terminal 300 receives and reproduces thestream data distributed from imaging apparatus 10, and thus can displaythe moving images shot by imaging apparatus 10 substantially in realtime. Imaging apparatus 10 also transmits, to server 400, the video filecreated by storing the data of the moving images shot by imaging unit105. The moving images in the video file do not require real timeprocessing, and hence can be made to have a larger data amount andhigher image quality than the moving images to be streaming-distributed.The video file received by server 400 is edited or is used for edition,for example.

In order to respond to a request that users want to obtain the videofile as early as possible, imaging apparatus 10 sometimes transmits thevideo file simultaneously with the streaming distribution.

However, the following problem can occur. When video distribution device100 simultaneously transmits the stream data and the video file on onecommunication route, the amount of data to be transmitted becomesexcessively larger than the communication capacity of the network, thetransmission of the stream data halts temporarily, and video receivingterminal 300 cannot display the moving images in real time, for example.Here, examples of the simultaneous transmission include the followingoperations:

-   -   data of the video file is transmitted via first network 200        while video distribution is performed via first network 200; and    -   video distribution is performed via second network 210 while the        video file is transmitted via second network 210.

In order to prevent such a problem from occurring, video distributiondevice 100 is configured to perform the video distribution via firstnetwork 200 for video distribution, and transmit general data via secondnetwork 210 for general data communication during the videodistribution.

In the conventional technology, even when the video distribution isperformed along a default route passing through the network for videodistribution, the following problem can occur:

-   -   when routing information including default route information is        acquired from the network for general data communication, and        the default route is updated to a route passing through the        network for general data communication, the subsequent video        distribution cannot be performed via the network for video        distribution.

In order to prevent such a problem from occurring, video distributiondevice 100 of the present exemplary embodiment has the followingconfiguration:

-   -   even when default route information is acquired from second        network 210 for general data communication during video        distribution, the video distribution via the network for video        distribution can be continued by preventing the in-use default        route from being changed in response to the default route        information.

Hereinafter, the configuration and operation of video distributiondevice 100 are described.

“First network 200 for video distribution” is not limited to use foronly video distribution. “Second network 210 for general datacommunication” does not mean that the transmission of general data islimited to this network. Video distribution device 100, during the videodistribution, distributes video data via “first network 200 for videodistribution” and transmits general data via “second network 210 forgeneral data communication”. When video distribution is not beingperformed, however, video distribution device 100 may transmit generaldata via “first network 200 for video distribution”.

[1-1-2. Configuration of Video Distribution Device]

Next, the configuration of video distribution device 100 of the presentexemplary embodiment is described.

In order to intelligibly show the operation described in the presentexemplary embodiment, the block diagram of FIG. 2 shows main blocksrelated to the present exemplary embodiment and omits the functions andblocks related to the other operations. For example, similarly to atypically used digital video camera, imaging apparatus 10 includes thefollowing elements:

-   -   a power supply;    -   a display unit (display or finder);    -   a command receiving unit (user interface) for receiving a        command from a user and sending it to a controller;    -   the controller for controlling each block of imaging apparatus        10 on the basis of the command or the like from the user;    -   a data storage unit for storing video data output from imaging        unit 105 into a recording medium (e.g. memory card or hard disk        drive); and    -   a recording medium mounting unit on which the recording medium        such as a memory card is detachably mounted.        However, these blocks perform substantially the same operations        as those of the similar blocks used in the typical digital video        camera. Therefore, in order to prevent the description from        becoming more redundant than necessary, the description and        drawing thereof are omitted.

Each block of FIG. 2 may be formed of an independent circuit, or may beconfigured to, with a processor, execute a program created so as toachieve the operations of one or more of the blocks of FIG. 2.

FIG. 2 is a block diagram schematically showing one configurationexample of video distribution device 100 in accordance with the firstexemplary embodiment.

Video distribution device 100 includes video distribution unit 110 as aspecific data distribution unit, network communication unit 120, routinginformation acquiring unit 130, video distribution determining unit 140as a specific data distribution determining unit, routing setting unit150, packet transfer unit 160, first communication device 170, andsecond communication device 180.

Video distribution unit 110 is configured to perform IP (InternetProtocol) communication with video receiving terminal 300 via firstcommunication device 170 and first network 200, and to convert the videodata output from imaging unit 105 into an IP packet and distribute(video distribution) it to video receiving terminal 300. Here, the videodata handled by video distribution unit 110 is not limited to the videodata output from imaging unit 105. For example, the video data may bevideo data that is stored in the recording medium included in imagingapparatus 10 (or, detachably mounted on imaging apparatus 10), or may bevideo data (or video signal) that is input from another imagingapparatus or a moving-picture reproducing apparatus.

Network communication unit 120 is configured to, when imaging apparatus10 performs IP communication other than video distribution, perform theIP communication with server 400 via second communication device 180 andsecond network 210. The IP communication is, for example, the access toWWW, file transfer to server 400, or transmission or reception of anelectronic mail. Hereinafter, “IP communication” is simply referred toas “communication”. When video distribution unit 110 is not distributingvideo data, network communication unit 120 performs communication alongthe default route at this time. For example, network communication unit120 sometimes communicates with server 400 via first communicationdevice 170 and first network 200.

Routing information acquiring unit 130 is configured to connect videodistribution device 100 to a network using a communication protocol suchas the DHCP or PPP. Routing information acquiring unit 130 is configuredto acquire routing information including default route information via anetwork connected to video distribution device 100 from a serverconnected to the network, and inform routing setting unit 150 of theacquired default route information. Here, the network is first network200 or second network 210, and the server is a DHCP server or PPPserver, for example.

Video distribution determining unit 140 is configured to determine“whether or not video distribution device 100 is distributing videodata” and output the determination result to routing setting unit 150.

Routing setting unit 150 is configured to hold the default routeinformation acquired from routing information acquiring unit 130, andinform packet transfer unit 160 of the default route information on thebasis of the video distribution state acquired from video distributiondetermining unit 140. Routing setting unit 150 includes a holding unit(not shown) for holding the default route information acquired fromrouting information acquiring unit 130. The details of these operationsof routing setting unit 150 are described later.

Packet transferring unit 160 is configured to transfer the IP packet,which is to be transmitted from video distribution device 100, to firstcommunication device 170 or second communication device 180 inaccordance with the content of the IP packet. Packet transferring unit160 is also configured to change (update) the default route on the basisof the default route information informed from routing setting unit 150.Hereinafter, this operation is referred to also as “acquiring thedefault route from routing setting unit 150”, for convenience sake. Whenthe transfer destination of the IP packet is not known, packet transferunit 160 determines the transfer destination of the IP packet on thebasis of the default route acquired from routing setting unit 150.Packet transferring unit 160 transfers the IP packet that is acquiredfrom first network 200 by first communication device 170 or the IPpacket that is acquired from second network 210 by second communicationdevice 180 to one of video distribution unit 110, network communicationunit 120, and routing information acquiring unit 130 in accordance withthe content of the IP packet.

The default route is routing information used when the transmissionsource cannot determine the transfer destination of the IP packet to betransmitted. Therefore, generally, the number of default routes used byone device is one. When video distribution unit 110 is distributingvideo data, however, packet transfer unit 160 operates so as to transferthe IP packet of the general data not by reference to the default routeset in packet transfer unit 160, but by reference to the default routeinformation held in routing setting unit 150 (as described later). Thedetails of the operation are described later.

First communication device 170 and second communication device 180 areconfigured to connect video distribution device 100 to a network andtransmit or receive the IP packet via the network. First communicationdevice 170 and second communication device 180 may be in conformity withany standard, for example, LTE, Ethernet (registered trademark), orWiFi. In the present exemplary embodiment, first communication device170 is set as a communication device for video distribution, and secondcommunication device 180 is set as a communication device for generaldata communication. However, the present exemplary embodiment is notlimited to this configuration. “First” and “second” may be setreversely.

It is preferable that video distribution device 100 includes both offirst communication device 170 and second communication device 180.However, the present exemplary embodiment is not limited to thisconfiguration. For example, video distribution device 100 is configuredto satisfy the following condition, for example:

-   -   video distribution device 100 includes a USB interface;    -   an LTE-compliant communication device, Ethernet (registered        trademark)-compliant communication device, or WiFi-compliant        communication device, which is configured to be connected the        USB interface, is connected to the USB interface of video        distribution device 100;    -   the communication device is used as both or one of first        communication device 170 and second communication device 180.        The number of communication devices included in video        distribution device 100 is not limited to two, but may be three        or more.

In the present exemplary embodiment, first communication device 170 isset as the communication device for video distribution, and secondcommunication device 180 is set as the communication device for generaldata communication. As discussed above, first communication device 170is not limited to use for only video distribution, the general data doesnot necessarily pass through only second communication device 180. Whenvideo data is not being distributed, first communication device 170 canpass the general data.

[1-2. Operation]

Next, the default route setting operation and IP packet transmittingoperation in video distribution device 100 having the above-mentionedconfiguration are described.

First, the default route setting operation when video distributiondevice 100 acquires default route information is described using FIG. 3.Next, the default route setting operation when video distribution device100 stops the video distribution is described using FIG. 4. Next, the IPpacket transmitting operation in video distribution device 100 isdescribed using FIG. 5.

[1-2-1. Default Route Setting Operation when Default Route Informationis Acquired]

FIG. 3 is a flowchart schematically showing one example of a defaultroute setting operation when video distribution device 100 acquiresdefault route information in accordance with the first exemplaryembodiment.

When video distribution device 100 is connected to first network 200 orsecond network 210, routing information acquiring unit 130 acquiresdefault route information from the network using a communicationprotocol such as the DHCP or PPP (step S10).

When default route information is not acquired in step S10 (No), routinginformation acquiring unit 130 performs the processing of step S10again.

Also after video distribution device 100 is connected to the network,routing information acquiring unit 130 regularly acquires the defaultroute information from the network using the DHCP or PPP.

The acquirement method of the default route information by routinginformation acquiring unit 130 is not limited to the DHCP or PPP, butmay be based on another method.

When the default route information is acquired in step S10 (Yes),routing information acquiring unit 130 informs routing setting unit 150of the acquired default route information and the communication deviceused for the acquirement of the default route information. In thepresent exemplary embodiment, routing information acquiring unit 130informs routing setting unit 150 of which of first communication device170 and second communication device 180 has been used.

Upon receiving the default route information from routing informationacquiring unit 130, routing setting unit 150 recognizes “whether or notvideo distribution device 100 is distributing video data” (step S11).This recognition can be performed based on the output from videodistribution determining unit 140 (namely, determination result ofwhether or not video distribution device 100 is distributing videodata).

In the present exemplary embodiment, video distribution determining unit140 is configured to, when it detects that video distribution device 100is in one of the following states, output the determination result of“video distribution device 100 is distributing video data”.

(1) Video distribution device 100 has accepted a user operation ofstarting the video distribution, but has not accepted a user operationof stopping the video distribution. These user operations are performedvia a command receiving unit (not shown) that receives a command fromthe user and sends it to a controller (not shown).(2) Video distribution device 100 has received a start request of thevideo distribution that is transmitted from video receiving terminal300, but has not received a stop request of the video distribution.

Therefore, when video distribution determining unit 140 detects thatvideo distribution device 100 is in none of the above-mentioned states,it outputs the determination result of “video distribution device 100 isnot distributing video data”.

Video distribution determining unit 140 of the present exemplaryembodiment is not limited to these configurations. However, videodistribution determining unit 140 may be configured to determine whetheror not video distribution device 100 is distributing video data on thebasis of a determination reference other than the above-mentioned ones.For example, video distribution determining unit 140 may be configuredto recognize the operation state of video distribution unit 110 anddetermine whether or not video distribution device 100 is distributingvideo data.

When it is recognized in step S11 (No) that video distribution device100 is not distributing video data, routing setting unit 150 informspacket transfer unit 160 of the default route information acquired instep S10. Based on the default route information, the default route(namely, default route set in packet transfer unit 160) in videodistribution device 100 is changed (step S14).

When video distribution device 100 is not distributing video data, thedefault route information informed to packet transfer unit 160 in stepS14 may have been acquired from either of first communication device 170and second communication device 180. In other words, when videodistribution device 100 is not distributing video data, the defaultroute may pass through either of first network 200 and second network210.

When it is recognized in step S11 (Yes) that video distribution device100 is distributing video data, routing setting unit 150 recognizeswhether or not the acquired default route information in step S10 hasbeen acquired from the communication device for video distribution (inthe present exemplary embodiment, first communication device 170) (stepS12).

When it is recognized in step S12 (Yes) that the acquired default routeinformation in step S10 has been acquired from first communicationdevice 170 for video distribution, routing setting unit 150 informspacket transfer unit 160 of the default route information acquired instep S10. Based on the default route information, the default route(namely, default route set in packet transfer unit 160) in videodistribution device 100 is changed (step S14).

The processing in step S14 sometimes corresponds to updating of thedefault route already set in packet transfer unit 160. For example, in aroute passing through a certain network (e.g. first network 200), oneroute is blocked by a device failure or the like and the route issometimes changed to another route by a manager. Alternatively, videodistribution device 100 radio-connected to a certain access point forradio communication is sometimes radio-connected to another access pointby movement or the like. When the default route set in packet transferunit 160 is not updated after such route change, there is a possibilitythat the video distribution is performed along the default route, whichpasses through the blocked route or the access point before themovement, and hence data does not arrive at video receiving terminal300. However, the default route is updated by the processing in stepS14, so that such a trouble can be avoided and the video distributioncan be continued.

When it is recognized in step S12 (No) that the acquired default routeinformation in step S10 has been acquired from second communicationdevice 180 for general data communication, routing setting unit 150keeps the default route information acquired in step S10 without change,and does not inform packet transfer unit 160. Therefore, the defaultroute of packet transfer unit 160 is not changed (step S13). When thedefault route information acquired from second communication device 180is set in packet transfer unit 160 during the video distribution, thereis a possibility that, after the setting, video distribution device 100cannot distribute video data from first communication device 170 tovideo receiving terminal 300. Since the default route set in packettransfer unit 160 is not changed, video distribution device 100 cancontinue the video distribution to video receiving terminal 300 that isperformed from first communication device 170 via first network 200.

After the processing in step S13, the process returns to step S10.

Each of above-mentioned step S10 to step S14 may be repeated. Thesequence of the steps may be changed in a range in which contradictionin the operations does not arise.

[1-2-2. Default Route Setting Operation when Video Distribution isStopped]

The default route setting operation when video distribution device 100stops video distribution in is described using FIG. 4.

FIG. 4 is a flowchart schematically showing one example of the defaultroute setting operation when video distribution device 100 stops videodistribution in accordance with the first exemplary embodiment.

Routing setting unit 150, based on the output from video distributiondetermining unit 140, recognizes whether or not video distributiondevice 100 has stopped the video distribution (step S20).

In the present exemplary embodiment, video distribution determining unit140 is configured to, when it detects that video distribution device 100is in one of the following states, output the determination result of“video distribution device 100 has stopped video distribution”.

(1) The user has performed an operation of making video distributiondevice 100 stop video distribution. This user operation is performed viaa command receiving unit (not shown) that receives a command from theuser and sends it to a controller (not shown).(2) Video distribution device 100 has received a stop request of thevideo distribution from video receiving terminal 300.(3) First communication device 170 for video distribution has beenseparated from first network 200 for video distribution.

Video distribution determining unit 140 of the present exemplaryembodiment is not limited to these configurations. However, videodistribution determining unit 140 may be configured to determine whetheror not video distribution device 100 has stopped the video distributionon the basis of a determination reference other than the above-mentionedones. For example, video distribution determining unit 140 may beconfigured to recognize the operation state of video distribution unit110 and determine whether or not video distribution device 100 hasstopped the video distribution.

When it is recognized in step S20 (No) that video distribution device100 has not stopped the video distribution, the processing of step S20is performed again.

When it is recognized in step S20 (Yes) that video distribution device100 has stopped the video distribution, routing setting unit 150recognizes whether or not the default route information is held (stepS21).

When it is recognized in step S21 (No) that the default routeinformation is not held, the processing is completed.

When it is recognized in step S21 (Yes) that the default routeinformation is held, routing setting unit 150 informs packet transferunit 160 of the held default route information. Thus, based on thedefault route information, the default route (namely, default route setin packet transfer unit 160) of video distribution device 100 is changed(step S22).

Each of above-mentioned step S20 to step S22 may be repeated. Thesequence of the steps may be changed in a range in which contradictionin the operations does not arise.

[1-2-3. IP Packet Transmitting Operation]

Next, the IP packet transmitting operation of video distribution device100 is described using FIG. 5.

FIG. 5 is a flowchart schematically showing one example of the IP packettransmitting operation of video distribution device 100 in accordancewith the first exemplary embodiment.

Packet transfer unit 160 determines whether or not the IP packet to betransmitted is an IP packet related to video distribution (step S30).

Packet transfer unit 160 is configured to perform this determination byrecognizing whether or not the communication protocol and port numberfor video distribution are applied to the IP packet. However, thepresent exemplary embodiment is not limited to this configuration. Thisdetermination may be performed on the basis of another reference. Forexample, packet transfer unit 160 may be configured to include areceiving interface dedicated to video distribution and to determinethat only the IP packet acquired via the receiving interface is an IPpacket related to the video distribution.

When it is determined in step S30 (Yes) that the IP packet to betransmitted is an IP packet related to the video distribution, packettransfer unit 160 transmits the IP packet along the default route set inpacket transfer unit 160—from first communication device 170 for videodistribution to video receiving terminal 300 via first network 200 forvideo distribution—(step S32).

When it is determined in step S30 (No) that the IP packet to betransmitted is an IP packet (namely, of general data) that is notrelated to the video distribution, packet transfer unit 160 recognizeswhether routing setting unit 150 holds the default route information(step S31).

When it is recognized in step S31 (Yes) that routing setting unit 150holds the default route information, packet transfer unit 160 refers tothe default route information held by routing setting unit 150 andtransmits the IP packet in accordance with the default route information(step S33).

When it is recognized in step S31 (No) that routing setting unit 150does not hold a default route, packet transfer unit 160 transmits the IPpacket along the default route of packet transfer unit 160, similarly tothe transmission of the IP packet related to video distribution (stepS32).

Each of above-mentioned step S30 to step S33 may be repeated. Thesequence of the steps may be changed in a range in which contradictionin the operations does not arise.

[1-3. Advantageous Effect or the Like]

Thus, in the present exemplary embodiment, video distribution device 100taken as an example of a data distribution device includes videodistribution unit 110 taken as an example of a specific datadistribution unit, video distribution determining unit 140 taken as anexample of a specific data distribution determining unit, and routingsetting unit 150. The specific data distribution unit (videodistribution unit 110) is configured to distribute the video data takenas an example of the specific data from first communication device 170that is connected to first network 200. The specific data distributiondetermining unit (video distribution determining unit 140) is configuredto determine whether or not the specific data distribution unit (videodistribution unit 110) is distributing the specific data (video data).Routing setting unit 150 is configured to satisfy the followingconditions:

-   -   based on the determination result of the specific data        distribution determining unit (video distribution determining        unit 140), the default route information acquired from the        network is used for changing the default route; and    -   when the specific data distribution determining unit (video        distribution determining unit 140) determines that the specific        data distribution unit (video distribution unit 110) is        distributing the specific data (video data), and the default        route information has been acquired from second communication        device 180 connected to second network 210, the default route        information is held without changing the default route.

Routing setting unit 150 is also configured to, when the specific datadistribution determining unit (video distribution determining unit 140)determines that the specific data distribution unit (video distributionunit 110) is distributing the specific data (video data), change thedefault route on the basis of the default route information acquiredfrom first communication device 170.

The data distribution device (video distribution device 100) isconfigured to, when the specific data distribution determining unit(video distribution determining unit 140) determines that the specificdata distribution unit (video distribution unit 110) is distributing thespecific data (video data), transmit general data other than thespecific data in accordance with the default route information held inrouting setting unit 150.

Routing setting unit 150 is also configured to, when the specific datadistribution determining unit (video distribution determining unit 140)recognizes that the distribution of the specific data (video data) hasbeen stopped, change the default route on the basis of the default routeinformation held in routing setting unit 150.

The data distribution device (video distribution device 100) may beconfigured to be mountable on imaging apparatus 10 including imagingunit 105 capable of performing video shooting, and may be alsoconfigured to set the video data output from imaging unit 105 to bespecific data.

The specific data may be stream data for distributing, in real time, thevideo data output from imaging unit 105, and general data other than thespecific data may include the data of the video file that is created bystoring the video data output from imaging unit 105.

Thus, in video distribution device 100, when default route informationis acquired via first communication device 170 for video distributionduring the video distribution, the default route is changed based on thedefault route information. When default route information is acquiredvia second communication device 180 for general data communicationduring the video distribution, the default route information is held inrouting setting unit 150, but the default route is not changed.

Therefore, during the video distribution, video distribution device 100keeps, without change, the default route set to pass through firstnetwork 200 for video distribution even when the default routeinformation is acquired from second network 210 for general datacommunication. Thus, video distribution device 100 can continue thevideo distribution along the default route passing through first network200.

In other words, video distribution device 100 can stably continue thevideo distribution by preventing the occurrence of the followingproblem:

-   -   although video distribution (for example, video distribution by        streaming) via a network for video distribution is intended to        be kept, the default route is changed so as to pass through        another network and a trouble occurs in the video distribution.

Even when a network configuration is employed where communication fromsecond network 210 for general data communication to video receivingterminal 300 is not allowed, video distribution device 100 can stablycontinue the video distribution to video receiving terminal 300. That isbecause video distribution device 100 does not perform the videodistribution along the default route passing through second network 210.

Video distribution device 100, during video distribution, performs thetransmission of general data by reference to the default routeinformation passing through second network 210. Here, the default routeinformation has been acquired from second network 210 for general datacommunication, and is held in routing setting unit 150. Thus, videodistribution device 100 can prevent the occurrence of the followingproblem during video distribution, for example:

-   -   video distribution (for example, transmission of stream data)        and transmission of general data are simultaneously performed        along one communication route, and hence the amount of data to        be transmitted becomes excessively larger than the communication        capacity of the network to temporarily halt the video        distribution.

Video distribution device 100 can perform these operations using aprotocol such as the DHCP or PPP. Therefore, the operation of previouslysetting the routing information that indicates the combination of thespecific communication partner and the specific communication device isnot required, though this operation has been required in theconventional technology. Therefore, video distribution device 100 doesnot require the following operation, either:

-   -   when the IP address of the communication partner or the IP        address of the router included in the routing information is        changed, the user changes the setting by himself/herself.

After the stop of the video distribution, video distribution device 100informs packet transfer unit 160 of the default route information heldin routing setting unit 150, changes the default route, and transmitsthe general data along the default route. Therefore, video distributiondevice 100 can transmit the general data also after the stop of thevideo distribution, similarly during the video distribution.

Other Exemplary Embodiments

Thus, the first exemplary embodiment has been described as an example ofa technology disclosed in the present application. However, thedisclosed technology is not limited to the exemplary embodiment. Thedisclosed technology can be also applied to the exemplary embodimenthaving undergone change, replacement, addition, or omission. A newexemplary embodiment may be created by combining the componentsdescribed in the first exemplary embodiment.

Another exemplary embodiment is described hereinafter.

FIG. 1 shows the configuration example where each of video receivingterminal 300 and server 400 is connected to one network. However, thenetwork system may be configured to prevent connection from secondnetwork 210 to video receiving terminal 300. The network system may beconfigured to prevent connection from first network 200 to server 400.

It may be allowed that routing setting unit 150 informs packet transferunit 160 of the held default route information when routing setting unit150 recognizes the stop of the video distribution, and hence comes intothe state where the default route information is not held. When videodistribution device 100 is not distributing video data, the defaultroute information acquired from the network does not need to be held inrouting setting unit 150. Therefore, the operation in step S32 may be apacket transfer operation performed when video distribution device 100is not distributing video data.

The present disclosure is applicable to a data distribution device andimaging apparatus capable of being connected to a plurality of networksusing a plurality of communication devices. Specifically, the presentdisclosure is applicable to a moving image pickup apparatus such as aprofessional-use video camera or consumer-use video camera, a stillimage pickup apparatus such as a digital still camera capable ofshooting a moving image, a smartphone, a tablet terminal, amoving-picture reproducing apparatus, a voice distribution apparatus, ora server.

What is claimed is:
 1. A data distribution device comprising: amultimedia data distribution unit to distribute, via a default route,multimedia data from a first communication device connected to a firstnetwork; a multimedia data distribution determining unit to determinewhether or not the multimedia data distribution unit is distributing themultimedia data; and a routing setting unit to, based on a determinationresult by the multimedia data distribution determining unit, use adefault route information acquired from the first network or a secondnetwork through the first communication device or a second communicationdevice to change the default route, and hold the default routeinformation without changing the default route when the multimedia datadistribution determining unit determines that the multimedia datadistribution unit is distributing the multimedia data and when thedefault route information has been acquired from the secondcommunication device connected to the second network, wherein therouting setting unit, when the multimedia data distribution determiningunit determines that the multimedia data distribution unit isdistributing the multimedia data and when default route information hasbeen acquired from the first communication device connected to the firstnetwork, changes the default route based on the default routeinformation acquired from the first communication device.
 2. The datadistribution device according to claim 1, wherein the data distributiondevice, when the multimedia data distribution determining unitdetermines that the multimedia data distribution unit is distributingthe multimedia data, transmits general data other than the multimediadata in accordance with the held default route information.
 3. The datadistribution device according to claim 1, wherein the routing settingunit, when the multimedia data distribution determining unit recognizesa stop of distribution of the multimedia data, changes the default routebased on the held default route information.
 4. An imaging apparatuscomprising: the data distribution device according to claim 1; and animaging unit for performing video shooting, wherein the imagingapparatus sets, as the multimedia data, video data output from theimaging unit.
 5. The imaging apparatus according to claim 4, wherein themultimedia data is stream data for distributing, in real time, the videodata output from the imaging unit, and general data other than themultimedia data includes data of a video file created by storing thevideo data output from the imaging unit.
 6. A data distribution devicecomprising: a multimedia data distribution unit to distribute, via adefault route, multimedia data from a first communication deviceconnected to a first network; a multimedia data distribution determiningunit to determine whether or not the multimedia data distribution unitis distributing the multimedia data; and a routing setting unit to,based on a determination result by the multimedia data distributiondetermining unit, use a default route information acquired from thefirst network or a second network through the first communication deviceor a second communication device to change the default route, and holdthe default route information without changing the default route whenthe multimedia data distribution determining unit determines that themultimedia data distribution unit is distributing the multimedia dataand when the default route information has been acquired from the secondcommunication device connected to the second network, wherein the datadistribution device, when the multimedia data distribution determiningunit determines that the multimedia data distribution unit isdistributing the multimedia data, transmits general data other than themultimedia data in accordance with the held default route information.7. A data distribution device comprising: a multimedia data distributionunit to distribute, via a default route, multimedia data from a firstcommunication device connected to a first network; a multimedia datadistribution determining unit to determine whether or not the multimediadata distribution unit is distributing the multimedia data; and arouting setting unit to, based on a determination result by themultimedia data distribution determining unit, use a default routeinformation acquired from the first network or a second network throughthe first communication device or a second communication device tochange the default route, and hold the default route information withoutchanging the default route when the multimedia data distributiondetermining unit determines that the multimedia data distribution unitis distributing the multimedia data and when the default routeinformation has been acquired from the second communication deviceconnected to the second network, wherein the routing setting unit, whenthe multimedia data distribution determining unit recognizes a stop ofdistribution of the multimedia data, changes the default route based onthe held default route information.